Sen. Ron Johnson's lawsuit challenging the legality of federal contributions to the health care plans of members of Congress and congressional staffers has a new ally: the Republican National Committee.

"Senator Ron Johnson is suing the Obama Administration for exempting Democrat Members of Congress from the ObamaCare law," the RNC petition said. "It's unfair to make American citizens live under a law that politicians are exempt from."

The RNC solicited support for the petition Sunday on Twitter, along with a graphic:

Johnson, a Wisconsin Republican, first told CQ Roll Call of his intentions regarding the lawsuit last September, shortly after filing comment with the Office of Personnel Management contesting the changes.

The OPM fix has preserved federal contributions for the staffers in both parties who have transitioned onto the District of Columbia's health care exchange, as required by the health care overhaul law.

The Republican National Committee's use of the Johnson lawsuit as a campaign issue follows court filings reported last week in which 38 GOP members of Congress backed Johnson in the litigation in federal court in Wisconsin.